The present invention relates generally to the field of electrical switchboards and panel boards having bus bars, and more particularly to a bus joint cover assembly for use in switchgear and panel board equipment.
Switchgear assemblies, switchboards and panelboards are general terms which cover metal enclosures, housing switching and interrupting devices such as fuses, and circuit breakers, along with associated control, instrumentation and metering devices. Such assemblies typically include associated bus bars, interconnections and supporting structures used for the distribution of electrical power. Low voltage switchgear and switchboards operate at voltages up to 600 volts and with continuous currents up to 5000 amps or higher. Such devices are also designed to withstand short circuit currents ranging up to 200,000 amps (3 phase rms symmetrical).
Typical switchgear equipment is composed of a lineup of several metal enclosed sections. Each section may have several circuit breakers stacked one above the other vertically in the front of the section with each breaker being enclosed in its own metal compartment. Each section has a vertical or section bus which supplies current to the breakers within the section via short horizontal branch buses. The vertical bus bars in each section are supplied with current by a horizontal main bus bar that runs through the lineup of metal enclosed sections. A typical arrangement includes bus bars for each electrical phase of a multiple phase system which may include three power phases and a neutral.
The bus bars typically are joined by bus bar joints in the switchgear panel board line-up. Bus bar joints typically are assembled with bolts that must be accessible for routine maintenance, for example, tightening or replacing bus bars. Bus bar assemblies typically increase in thickness as the current rating of the switchgear equipment increases. It is also typical to provide insulation of various components within a switchgear a panel board enclosure including a cover of the bus bar joints.
Thus, there is a need for a bus bar cover assembly for use in switchgear equipment that will enclose a bus bar joint. There is a further need for a bus joint cover assembly that provides access to fasteners within the bus bar joint. There is an additional need for a bus bar cover assembly that can accommodate various current ratings (sizes) of bus bar joint.